1. Field of the Invention
The present invention is directed to an aortic replacement valve, as well as methods and systems for transcatheter placement of the aortic replacement valve.
2. Description of the Prior Art
There are many aortic replacement valves that are available for trans-catheter replacement of a defective aortic valve. The current aortic valve designs are made of a metal frame with tissue valves, and skirt sutured on to the frame. The frame is mostly a skeleton-type design, allowing it to be crimped to a small profile for insertion and expansion in situ.
Unfortunately, the current aortic valve designs still suffer from some important drawbacks.
First, coronary access remains an issue. With the wire braided or slotted tube designs utilized by the current aortic valve frames, the cells are condensely-packed to achieve the required expansion force. The condensed cells could be too small to allow for catheters to pass through, and thereby make the later coronary access by catheters (for angioplasty and stenting) more difficult.
Second, there is often a need to resheath the partially deployed valve assembly. The current aortic valves are either not retrievable upon partial deployment at regular body temperature due to its expansion force, or are retrievable only by reducing the frame's expansion force. In the latter situation, the reduced expansion force limits the suitability of the valve assembly to replacement of severely calcified native valves.
Third, perivalvular leak (PVL) is still a problem with many of the existing transcatheter aortic valve assemblies. Many of the first generation valve assemblies did not address the PVL issue. The later generations started to add features, such as cuffs, to the inflow section. The cuff is essentially a separate component attached to the frame on the outside. However, adding such cuffs increases the profile of the valve assembly when crimped, thereby requiring a larger delivery system.
Thus, there remains a need for a transcatheter aortic valve assembly that overcomes the shortcomings described above.